Cluster view for storage devices

ABSTRACT

One or more techniques and/or systems are provided for generating a macroscopic cluster view of storage devices, as opposed to merely an isolated view from an individual node. For example, nodes within a node cluster may be queried for storage device reports comprising storage device information regarding storage devices with which the nodes are respectively connected (e.g., I/O performance statistics, path connections, storage device attributes, status, error history, etc.). The storage device reports may be aggregated together to define one or more storage device data structures (e.g., a storage device data structure comprising one or more tables that may be populated with storage device information). In this way, the cluster view may be generated based upon querying one or more storage device data structures (e.g., an error cluster view, a storage device cluster view, a node summary cluster view, etc.).

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/237,369, filed on Sep. 20, 2011, entitled “CLUSTER VIEW FOR STORAGEDEVICES”, at least some of which may be incorporated herein.

FIELD

The instant disclosure pertains to generating a cluster view of storagedevices from an aggregated viewpoint of a node cluster.

BACKGROUND

A network storage environment may comprise a node cluster (e.g., storageservers) of nodes that collaborate together to manage various aspects ofdata storage associated with attached storage devices (e.g., data volumecreation, read/write access, logical unit number (LUN) creation, virtualand physical data formatting, etc.). For example, the node cluster mayprovide host computing devices with read/write access to data stored onstorage devices. In this way, a host computing device may connect to anode that may provide the host computing device with access to datastored on storage devices connected to the node. In one example, a nodecluster may comprise node A, node B, node C, and/or other nodes. Node Amay be connected to storage device 1 and storage device 2, node B may beconnected to storage device 3, node C may be connected to storage device2 and storage device 5, etc. A user may desire to startup a virtualmachine on a desktop host computing device using a virtual machinehosting application. The virtual machine hosting application may beconfigured to retrieve virtual machine data of the virtual machine fromstorage devices accessible through the node cluster. In particular, thevirtual machine hosting application may access node C because node C isconnected to storage device 2 and storage device 5, which may store thevirtual machine data. In this way, node C may provide the virtualmachine hosting application on the desktop host computing device withaccess to the virtual machine data stored across storage device 2 andstorage device 5.

Conventional network storage environments may provide reporting toolsthat generate views of storage information from isolated viewpoints ofindividual nodes within the node cluster (e.g., storage informationknown to node A, storage information known to node B, etc.).Unfortunately, such conventional reporting techniques merely provideviews that are based upon isolated reports from the respective nodes.For example, an administrator of a node cluster may request a view ofstorage devices attached to the node cluster. Accordingly, the nodes maybe individually queried to determine what storages devices areaccessible to the respective nodes. In this way, the administrator maybe presented with a view of information derived from isolated reports ofstorage information that is known to the nodes individually. Forexample, the view may specify that node D reported information regardingstorage device 3, node E reported information regarding storage device 3and 5, node F reported information regarding storage device 6, node Greported information regarding storage device 3 and 5, etc. Because thereports from the nodes are isolated, the view may comprise a significantamount of redundant and/or overlapping information (e.g., informationregarding device 3 may have been reported three times by node D, node E,and node G). Thus, the administrator may not be provided with anefficient or adequate view of what the node cluster knows as a singlecluster unit operating together, but merely with what individual nodesreported.

SUMMARY

The disclosure relates to one or more techniques and/or systems thatgenerate a cluster view of one or more storage devices. That is, acluster view may be generated that provides a view of storage deviceinformation from an aggregated viewpoint of a node cluster operatingtogether, as opposed to from a viewpoint based upon isolate reports fromindividual nodes (e.g., what storage devices the node cluster sees, asopposed to what storage devices the individuals nodes see). Inparticular, storage device reports comprising storage device informationreported from nodes within a node cluster may be aggregated togetherinto storage device data structures for respective storage devices(e.g., individualized storage device data structure per storage device).In this way, a cluster view may be generated utilizing one or morestorage device data structures.

In one example, respective nodes within a node cluster may be queriedfor storage device reports. In particular, a node may be queried for astorage device report associated with one or more storage devicesconnected to the node (e.g., a storage application programming interface(API) on the node may be queried). The storage device report maycomprise storage device information reported back by one or more storagesubsystems associated with the storage API (e.g., a device driver may beconfigured to provide a device status, such as an ability to accept I/Orequests; a first subsystem may be configured to query a storage devicefor storage device attribute information, such as model, vendor, pathconnections from the storage device to one or more nodes, etc.; a secondsubsystem may be configured to determine I/O performance statistics,such as read/write rates, latency, errors, etc.; and/or othersubsystems). In this way, the storage device report may comprise storagedevice information specifying a list of path connections from thestorage device to one or more nodes and/or storage device configurationand statistical information (e.g., I/O performance statistics, storagedevice attribute information, storage device ownership, error history,etc.). It may be appreciated that one example of one or more storagedevice reports is shown and further described in FIG. 6.

The storage device reports may be aggregated together to define storagedevice data structures for the storage devices (e.g., storage deviceinformation reported by various nodes may be correlated together tocreate an individualized storage device data structure for respectivestorage devices). For example, a storage device specified within astorage device report may be identified (e.g., node A may report storagedevice information associated with storage device 1). A storage devicedata structure for the storage device may be defined based upon storagedevice information within the storage device report (e.g., a new storagedevice data structure may be created or an existing storage device datastructure may be updated). It may be appreciated that one example of astorage device data structure is shown and further described in FIG. 7.For example, supplemental information may be added into the storagedevice data structure, non-supplemental redundant information may bediscarded, and/or conflicting information may be discarded or used tooverwrite current information based upon the role of the node reportingsuch information (e.g., information from an ownership node may bepreferred over information from a non-ownership node). In this way,storage device data structures may be defined for the respective storagedevices based upon aggregating the storage device information within thestorage device reports. It may be appreciated that in one example, asingle storage device data structure may comprise a complete view of astorage device from an aggregate viewpoint of the node cluster.

It may be appreciated that aggregating storage device reports to definestorage device data structures for storage devices allows for thegeneration of cluster views that provide an aggregated viewpoint of thenode cluster. Without the storage device data structures, informationabout storage devices and/or the storage cluster may be limited toisolated viewpoints of storage devices from individual nodes. That is,various cluster views may be generated utilizing one or more storagedevice data structures. Such views may provide storage deviceinformation based upon an aggregate viewpoint of the node clusteroperating together, rather than isolated viewpoints from individualnodes. A cluster view may be generated based upon information within oneor more storage device data structures. For example, a query may beconstructed, and executed against one or more storage device datastructures to create a cluster view (e.g., “find storage devices whereRPM>7200 and error count=0 and status=active”). In this way, a plethoraof different queries may be constructed to generate different clusterviews. It may be appreciated that a query may be based upon various(e.g., predefined) rules and/or query terms that may be constructedtogether, which may improve precision of storage device data fetching(e.g., redundant data may be excluded based upon the query terms and/orrules of a query).

In one example, an error cluster view may be generated by querying oneor more storage device data structures to identify storage devicesassociated with at least one error from the viewpoint of the nodecluster. It may be appreciated that one example of an error cluster viewis shown and further described in FIG. 9. In another example, a nodesummary cluster view may be generated by querying one or more storagedevice data structures to provide a comprehensive cluster view ofstorage devices and storage device connectivity within the node cluster(e.g., the node summary cluster view may illustrate from the perspectiveof the node cluster that storage device 1 is connected to node A,storage device 2 is connected to node B and node C, storage device 3 isconnected to node B, etc.). It may be appreciated that one example of anode summary cluster view is shown and further described in FIG. 8. Inanother example, a storage device cluster view of a storage device maybe generated by querying a storage device data structure associated withthe storage device. The storage device cluster view may comprise pathconnections from the storage device to one or more nodes, storage deviceconfiguration and statistical information, error history, and/or otherstorage device information. It may be appreciated that one example of astorage device cluster view is shown and further described in FIG. 10.In this way, various cluster views may be generated utilizing thestorage device data structures, which may provide a comprehensive viewof storage from the viewpoint of the node cluster, rather than isolatedviews of what nodes individually see.

To the accomplishment of the foregoing and related ends, the followingdescription and annexed drawings set forth certain illustrative aspectsand implementations. These are indicative of but a few of the variousways in which one or more aspects may be employed. Other aspects,advantages, and novel features of the disclosure will become apparentfrom the following detailed description when considered in conjunctionwith the annexed drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a component block diagram illustrating an example clusterednetwork in accordance with one or more of the provisions set forthherein.

FIG. 2 is a component block diagram illustrating an example data storagesystem in accordance with one or more of the provisions set forthherein.

FIG. 3 is a flow chart illustrating an exemplary method of generating acluster view of one or more storage devices.

FIG. 4 is a flow chart illustrating an exemplary method of presenting acluster view of one or more storage devices.

FIG. 5 is a component block diagram illustrating an exemplary system forgenerating a cluster view of one or more storage devices.

FIG. 6 is an illustration of an example of one or more storage devicereports.

FIG. 7 is an illustration of an example of a data structure for astorage device.

FIG. 8 is an illustration of an example of a node summary cluster view.

FIG. 9 is an illustration of an example of an error cluster view.

FIG. 10 is an illustration of an example of a storage device clusterview.

FIG. 11 is an example of a computer readable medium in accordance withone or more of the provisions set forth herein.

DETAILED DESCRIPTION

Some examples of the claimed subject matter are now described withreference to the drawings, where like reference numerals are generallyused to refer to like elements throughout. In the following description,for purposes of explanation, numerous specific details are set forth inorder to provide a thorough understanding of the claimed subject matter.It may be evident, however, that the claimed subject matter may bepracticed without these specific details. Nothing in this detaileddescription is admitted as prior art.

As nodes (e.g., storage servers) within a node cluster (e.g., a networkstorage environment) become increasingly interconnected and operatetogether as a self-aware cluster, it may be advantageous to providecomprehensive cluster views of storage information from a viewpoint ofthe node cluster, as opposed to from a viewpoint based upon isolatedreports from individual nodes. Unfortunately, current reporting toolsmay provide views of storage information from the viewpoint ofindividual nodes (e.g., information known to a single node withoutregard to what information another node knows). Such views may providean inadequate view of storage information (e.g., a significant amount ofredundant and/or overlapping data may be reported by nodes and/orpresented within a view because information reported by the nodes maynot be aggregated together).

Accordingly, a cluster view of one or more storage devices may begenerated based upon aggregated storage device reports from nodes withina node cluster as provided herein. In particular, storage device reportsmay be received from nodes within the node cluster. The storage devicereports may comprise storage device information (e.g., a list of pathconnections from a storage device to one or more nodes and/or storagedevice configuration and statistical information, such as I/Operformance, error history, ownership, storage device status andattributes, etc.). The storage device reports may be aggregated todefine storage device data structures for storage devices (e.g., anordered sequence of storage device data structures associated withcorresponding storage devices may be maintained, where a single storagedevice data structure may comprise a complete view of a storage devicefrom an aggregate viewpoint of the node cluster). In this way, storagedevice data structures may be utilized to generate a cluster view ofstorage information from the viewpoint of the node cluster (e.g., a widevariety of queries may be constructed using various rules and/or queryterms, which may be executed against one or more storage device datastructures to extract information to populate different cluster views).For example, a single API may be used to fetch details about one or morestorage devices on a per-storage device basis.

To provide context for cluster view generation, FIG. 1 illustrates aclustered network environment 100 (e.g., a node cluster), and FIG. 2illustrates an embodiment of a data storage system 200 (e.g., comprisinga node) that may be implemented to store and manage data within one ormore storage devices of which a cluster view may be generated. It willbe appreciated that where the same or similar components, elements,features, items, modules, etc. are illustrated in later figures but werepreviously discussed with regard to prior figures, that a similar (e.g.,redundant) discussion of the same may be omitted when describing thesubsequent figures (e.g., for purposes of simplicity and ease ofunderstanding).

FIG. 1 is a block diagram illustrating an example clustered networkenvironment 100 that may implement at least some embodiments of thetechniques and/or systems described herein. The example environment 100comprises data storage systems 102 and 104 that are coupled over acluster fabric 106, such as a computing network embodied as a privateInfiniband or Fibre Channel (FC) network facilitating communicationbetween the storage systems 102 and 104 (and one or more modules,component, etc. therein, such as , nodes 116 and 118, for example). Itwill be appreciated that while two data storage systems 102 and 104 andtwo nodes 116 and 118 are illustrated in FIG. 1, that any suitablenumber of such components is contemplated. Similarly, unlessspecifically provided otherwise herein, the same is true for othermodules, elements, features, items, etc. referenced herein and/orillustrated in the accompanying drawings. That is, a particular numberof components, modules, elements, features, items, etc. disclosed hereinis not meant to be interpreted in a limiting manner.

It will be further appreciated that clustered networks are not limitedto any particular geographic areas and can be clustered locally and/orremotely. Thus, in one embodiment a clustered network can be distributedover a plurality of storage systems and/or nodes located in a pluralityof geographic locations; while in another embodiment a clustered networkcan include data storage systems (e.g., 102, 104) residing in a samegeographic location (e.g., in a single onsite rack of data storagedevices).

In the illustrated example, one or more clients 108, 110 which maycomprise, for example, personal computers (PCs), computing devices usedfor storage (e.g., storage servers), and other computers or peripheraldevices (e.g., printers), are coupled to the respective data storagesystems 102, 104 by storage network connections 112, 114. Networkconnection may comprise a local area network (LAN) or wide area network(WAN), for example, that utilizes Network Attached Storage (NAS)protocols, such as a Common Internet File System (CIFS) protocol or aNetwork File System (NFS) protocol to exchange data packets.Illustratively, the clients 108, 110 may be general-purpose computersrunning applications, and may interact with the data storage systems102, 104 using a client/server model for exchange of information. Thatis, the client may request data from the data storage system, and thedata storage system may return results of the request to the client viaone or more network connections 112, 114.

The nodes 116, 118 on clustered data storage systems 102, 104 cancomprise network or host nodes that are interconnected as a cluster toprovide data storage and management services, such as to an enterprisehaving remote locations, for example. Such a node in a data storage andmanagement network cluster environment 100 can be a device attached tothe network as a connection point, redistribution point or communicationendpoint, for example. A node may be capable of sending, receiving,and/or forwarding information over a network communications channel, andcould comprise any device that meets any or all of these criteria. Oneexample of a node may be a data storage and management server attachedto a network, where the server can comprise a general purpose computeror a computing device particularly configured to operate as a server ina data storage and management system.

As illustrated in the exemplary environment 100, nodes 116, 118 cancomprise various functional components that coordinate to providedistributed storage architecture for the cluster. For example, the nodescan comprise a network module 120, 122 (e.g., N-Module, or N-Blade) anda data module 124, 126 (e.g., D-Module, or D-Blade). Network modules120, 122 can be configured to allow the nodes 116, 118 to connect withclients 108, 110 over the network connections 112, 114, for example,allowing the clients 108, 110 to access data stored in the distributedstorage system. Further, the network modules 120, 122 can provideconnections with one or more other components through the cluster fabric106. For example, in FIG. 1, a first network module 120 of first node116 can access a second data storage device 130 by sending a requestthrough a second data module 126 of a second node 118.

Data modules 124, 126 can be configured to connect one or more datastorage devices 128, 130, such as disks or arrays of disks, flashmemory, or some other form of data storage, to the nodes 116, 118. Thenodes 116, 118 can be interconnected by the cluster fabric 106, forexample, allowing respective nodes in the cluster to access data on datastorage devices 128, 130 connected to different nodes in the cluster.Often, data modules 124, 126 communicate with the data storage devices128, 130 according to a storage area network (SAN) protocol, such asSmall Computer System Interface (SCSI) or Fiber Channel Protocol (FCP),for example. Thus, as seen from an operating system on a node 116, 118,the data storage devices 128, 130 can appear as locally attached to theoperating system. In this manner, different nodes 116, 118, etc. mayaccess data blocks through the operating system, rather than expresslyrequesting abstract files.

It should be appreciated that, while the example embodiment 100illustrates an equal number of N and D modules, other embodiments maycomprise a differing number of these modules. For example, there may bea plurality of N and/or D modules interconnected in a cluster that doesnot have a one-to-one correspondence between the N and D modules. Thatis, different nodes can have a different number of N and D modules, andthe same node can have a different number of N modules than D modules.

Further, a client 108, 110 can be networked with the nodes 116, 118 inthe cluster, over the networking connections 112, 114. As an example,respective clients 108, 110 that are networked to a cluster may requestservices (e.g., exchanging of information in the form of data packets)of a node 116, 118 in the cluster, and the node 116, 118 can returnresults of the requested services to the clients 108, 110. In oneembodiment, the clients 108, 110 can exchange information with thenetwork modules 120, 122 residing in the nodes (e.g., network hosts)116, 118 in the data storage systems 102, 104.

In one embodiment, the data storage devices 128, 130 comprise volumes132, which is an implementation of storage of information onto diskdrives or disk arrays or other storage (e.g., flash) as a file-systemfor data, for example. Volumes can span a portion of a disk, acollection of disks, or portions of disks, for example, and typicallydefine an overall logical arrangement of file storage on disk space inthe storage system. In one embodiment a volume can comprise stored dataas one or more files that reside in a hierarchical directory structurewithin the volume.

Volumes are typically configured in formats that may be associated withparticular storage systems, and respective volume formats typicallycomprise features that provide functionality to the volumes, such asproviding an ability for volumes to form clusters. For example, where afirst storage system may utilize a first format for their volumes, asecond storage system may utilize a second format for their volumes.

In the example environment 100, the clients 108, 110 can utilize thedata storage systems 102, 104 to store and retrieve data from thevolumes 132. In this embodiment, for example, the client 108 can senddata packets to the N-module 120 in the node 116 within data storagesystem 102. The node 116 can forward the data to the data storage device128 using the D-module 124, where the data storage device 128 comprisesvolume 132A. In this way, in this example, the client can access thestorage volume 132A, to store and/or retrieve data, using the datastorage system 102 connected by the network connection 112. Further, inthis embodiment, the client 110 can exchange data with the N-module 122in the host 118 within the data storage system 104 (e.g., which may beremote from the data storage system 102). The host 118 can forward thedata to the data storage device 130 using the D-module 126, therebyaccessing volume 1328 associated with the data storage device 130.

It may be appreciated that generation of a cluster view of one or morestorage devices may be implemented within clustered network environment100. For example, a node query component configured to query nodes(e.g., nodes 116, 118), a data structure component configured to definestorage device data structures for storage devices (e.g., data storedevices 128, 130), and/or a cluster view component configured togenerate a cluster view from the viewpoint of the node cluster (e.g.,clustered network environment 100) may be implemented within theclustered network environment 100. For example, such components may beimplemented within clients 108, 110, nodes 116, 118, and/or other nodes,such as a centralized node, not illustrated.

FIG. 2 is an illustrative example of a data storage system 200 (e.g.,102, 104 in FIG. 1), providing further detail of an embodiment ofcomponents that may implement one or more of the techniques and/orsystems described herein. The example data storage system 200 comprisesa node 202 (e.g., host nodes 116, 118 in FIG. 1), and a data storagedevice 234 (e.g., data storage devices 128, 130 in FIG. 1). The node 202may be a general purpose computer, for example, or some other computingdevice particularly configured to operate as a storage server. A client205 (e.g., 108, 110 in FIG. 1) can be connected to the node 202 over anetwork 216, for example, to provides access to files and/or other datastored on the data storage device 234.

The data storage device 234 can comprise mass storage devices, such asdisks 224, 226, 228 of a disk array 218, 220, 222. It will beappreciated that the techniques and systems, described herein, are notlimited by the example embodiment. For example, disks 224, 226, 228 maycomprise any type of mass storage devices, including but not limited tomagnetic disk drives, flash memory, and any other similar media adaptedto store information, including, for example, data (D) and/or parity (P)information.

The node 202 comprises one or more processors 204, a memory 206, anetwork adapter 210, a cluster access adapter 212, and a storage adapter214 interconnected by a system bus 236. The storage system 200 alsoincludes an operating system 208 installed in the memory 206 of the node202 that can, for example, implement a Redundant Array of Independent(or Inexpensive) Disks (RAID) optimization technique to optimize areconstruction process of data of a failed disk in an array.

The operating system 208 can also manage communications for the datastorage system, and communications between other data storage systemsthat may be in a clustered network, such as attached to a cluster fabric215 (e.g., 106 in FIG. 1). Thus, the host 202 can to respond to clientrequests to manage data on the data storage device 200 (e.g., oradditional clustered devices) in accordance with these client requests.The operating system 208 can often establish one or more file systems onthe data storage system 200, where a file system can include softwarecode and data structures that implement a persistent hierarchicalnamespace of files and directories, for example. As an example, when anew data storage device (not shown) is added to a clustered networksystem, the operating system 208 is informed where, in an existingdirectory tree, new files associated with the new data storage deviceare to be stored. This is often referred to as “mounting” a file system.

In the example data storage system 200, memory 206 can include storagelocations that are addressable by the processors 204 and adapters 210,212, 214 for storing related software program code and data structures.The processors 204 and adapters 210, 212, 214 may, for example, includeprocessing elements and/or logic circuitry configured to execute thesoftware code and manipulate the data structures. The operating system208, portions of which are typically resident in the memory 206 andexecuted by the processing elements, functionally organizes the storagesystem by, among other things, invoking storage operations in support ofa file service implemented by the storage system. It will be apparent tothose skilled in the art that other processing and memory mechanisms,including various computer readable media, may be used for storingand/or executing program instructions pertaining to the techniquesdescribed herein. For example, the operating system can also utilize oneor more control files (not shown) to aid in the provisioning of virtualmachines.

The network adapter 210 includes the mechanical, electrical andsignaling circuitry needed to connect the data storage system 200 to aclient 205 over a computer network 216, which may comprise, among otherthings, a point-to-point connection or a shared medium, such as a localarea network. The client 205 (e.g., 108, 110 of FIG. 1) may be ageneral-purpose computer configured to execute applications. Asdescribed above, the client 205 may interact with the data storagesystem 200 in accordance with a client/host model of informationdelivery.

The storage adapter 214 cooperates with the operating system 208executing on the host 202 to access information requested by the client205. The information may be stored on any type of attached array ofwriteable media such as magnetic disk drives, flash memory, and/or anyother similar media adapted to store information. In the example datastorage system 200, the information can be stored in data blocks on thedisks 224, 226, 228. The storage adapter 214 can includes input/output(I/O) interface circuitry that couples to the disks over an I/Ointerconnect arrangement, such as a storage area network (SAN) protocol(e.g., Small Computer System Interface (SCSI), iSCSI, hyperSCSI, FiberChannel Protocol (FCP)). The information is retrieved by the storageadapter 214 and, if necessary, processed by the one or more processors204 (or the storage adapter 214 itself) prior to being forwarded overthe system bus 236 to the network adapter 210 (and/or the cluster accessadapter 212 if sending to another node in the cluster) where theinformation is formatted into a data packet and returned to the client205 over the network connection 216 (and/or returned to another nodeattached to the cluster over the cluster fabric 215).

In one embodiment, storage of information on arrays 218, 220, 222 can beimplemented as one or more storage “volumes” 230, 232 that are comprisedof a cluster of disks 224, 226, 228 defining an overall logicalarrangement of disk space. The disks 224, 226, 228 that comprise one ormore volumes are typically organized as one or more groups of RAIDs. Asan example, volume 230 comprises an aggregate of disk arrays 218 and220, which comprise the cluster of disks 224 and 226.

In one embodiment, to facilitate access to disks 224, 226, 228, theoperating system 208 may implement a file system (e.g., write anywherefile system) that logically organizes the information as a hierarchicalstructure of directories and files on the disks. In this embodiment,respective files may be implemented as a set of disk blocks configuredto store information, such as data (D) and/or parity (P), whereas thedirectory may be implemented as a specially formatted file in whichother files and directories are stored.

Whatever the underlying physical configuration within this data storagesystem 200, data can be stored as files within physical and/or virtualvolumes, which can be associated with respective volume identifiers,such as file system identifiers (FSIDs), which can be 32-bits in lengthin one example.

A physical volume, which may also be referred to as a “traditionalvolume” in some contexts, corresponds to at least a portion of physicalmemory whose address, addressable space, location, etc. doesn't change,such as at least some of one or more data storage devices 234 (e.g., aRedundant Array of Independent (or Inexpensive) Disks (RAID system)).Typically the location of the physical volume doesn't change in that the(range of) address(es) used to access it generally remains constant.

A virtual volume, in contrast, is stored over an aggregate of disparateportions of different physical storage devices. The virtual volume maybe a collection of different available portions of different physicalmemory locations, such as some available space from each of the disks224, 226, 228. It will be appreciated that since a virtual volume is not“tied” to any one particular storage device, a virtual volume can besaid to include a layer of abstraction or virtualization, which allowsit to be resized and/or flexible in some regards.

Further, a virtual volume can include one or more logical unit numbers(LUNs) 238, directories 236, qtrees 235, and files 240. Among otherthings, these features, but more particularly LUNS, allow the disparatememory locations within which data is stored to be identified, forexample, and grouped as data storage unit. As such, the LUNs 238 may becharacterized as constituting a virtual disk or drive upon which datawithin the virtual volume is stored within the aggregate. For example,LUNs are often referred to as virtual drives, such that they emulate ahard drive from a general purpose computer, while they actually comprisedata blocks stored in various parts of a volume.

In one embodiment, one or more data storage devices 234 can have one ormore physical ports, wherein each physical port can be assigned a targetaddress (e.g., SCSI target address). To represent respective volumesstored on a data storage device, a target address on the data storagedevice can be used to identify one or more LUNs 238. Thus, for example,when the host 202 connects to a volume 230, 232 through the storageadapter 214, a connection between the host 202 and the one or more LUNs238 underlying the volume is created.

In one embodiment, respective target addresses can identify multipleLUNs, such that a target address can represent multiple volumes. The I/Ointerface, which can be implemented as circuitry and/or software in thestorage adapter 214 or as executable code residing in memory 206 andexecuted by the processors 204, for example, can connect to volume 230by using one or more addresses that identify the LUNs 238.

It may be appreciated that a cluster view of one or more storage devicesmay be generated based upon storage device data structures defined usingstorage device reports from one or more nodes (node 202). For example, astorage device cluster view of data storage device 234 may be generatedbased upon a storage device data structure for data storage device 234,which may have been defined based upon a storage device report from node202 and/or other nodes connected to data storage device 234.

One embodiment of generating a cluster view of one or more storagedevices is illustrated by exemplary method 300 in FIG. 3. At 302, themethod starts. At 304, respective nodes within a node cluster may bequeried for storage device reports. In particular, at 306, a node may bequeried for a storage device report associated with one or more storagedevices connected to the node (e.g., a storage application programminginterface (API) on the node may be queried). For example, the storageAPI may be associated with one or more subsystems and/or device driversconfigured to retrieve storage device information that may be populatedwithin the storage device report (e.g., a first subsystem may query astorage device for storage device attribute information, such as model,vendor, path connections from the storage device to one or more nodes,etc.; a second subsystem may determine I/O performance statistics, suchas read/write rates, latency, errors, etc.; and/or other subsystems maygather other storage device information).

At 308, the storage device report comprising storage device informationmay be received from the node. It may be appreciated that one example ofone or more storage device reports is shown and further described inFIG. 6. In one example, the storage device information may comprise alist of connections from a storage device to one or more nodes and/orstorage device configuration and statistical information associated withone or more storage devices connected to the node. For example, storagedevice configuration and statistical information may comprise I/Operformance statistics (e.g., read/write operations, read/write rates,blocks read/written, latency, time powered on, I/O errors, etc.),storage device status information (e.g., ability and readiness to acceptI/O request), storage device role information (e.g., hot replacementspare, offline, online, part of a RAID, etc.), storage device ownershipinformation (e.g., whether a node is an owner or not of a storagedevice), storage device attribute information (e.g., vendor, model,serial number, RPM, disk type, firmware version, etc.), error history,and/or a variety of other information. It may be appreciated that in oneexample, the storage APIs of respective nodes within the node clustermay be queried in parallel. In this way, one or more storage devicereports may be received substantially concurrently from nodes within thenode cluster.

At 310, respective storage device reports may be aggregated to defineone or more storage device data structures for storage devices. It maybe appreciated that one example of one or more storage device datastructures is shown and further described in FIG. 7. In particular, at312, a storage device specified within a storage device report may beidentified. At 314, a storage device data structure for the storagedevice may be defined for the storage device based upon storage deviceinformation within the storage device report. In one example, if thestorage device data structure does not exist, then the storage devicedata structure may be created and/or populated with storage deviceinformation from the storage device report.

In another example where the storage device data structure exists,supplemental information within the storage device report may be addedinto the storage device data structure (e.g., current information withinthe storage device data structure may specify that storage device 2 isconnected to node A, while supplemental information within the storagedevice report may specify that storage device 2 is connected to node C,and thus the connection to node C may be added into the storage devicedata structure). In another example, where the storage device datastructure exists, non-supplementary redundant information may bediscarded (e.g., current information within the storage device datastructure may specify that storage device 2 has a model number 123456,while non-supplementary redundant information within the storage devicereport may specify that storage device 2 has a model number 123456, andthus may be discarded to avoid redundant data).

In another example where the storage device data structure exists, if apreferred node (e.g., a node having ownership over the storage device)reported conflicting information within the storage device report, thenthe conflicting information may overwrite current information within thestorage device data structure (e.g., current information within astorage device data structure for storage device (5) reported by node Z,a spare node for storage device (5), may specify that no I/O operationshave been performed recently, while conflicting information within thestorage device report reported by node C, an ownership node of storagedevice (5), may specify that 120 I/O operations have been performedrecently, and thus the current information of no I/O operations reportedby spare node Z may be replaced in the data structure with theconflicting information of 120 I/O operations because node C, theownership node, may be performing I/O operations whereas node Z, a sparenode, may be in an inactive state). Otherwise, if the node that reportedthe current information within the storage device data structure ispreferred, then the (subsequent) conflicting information may bediscarded (e.g., information from node C may not overwrite informationfrom node Z where node Z is preferred over node C).

The storage device data structure may comprise I/O performancestatistics for the storage device (e.g., latency, read/write operations,etc.), path connections between the storage device and one or morenodes, storage device status information (e.g., availability to acceptI/O request), storage device role information (e.g., active, hot spare,inactive, etc.), storage device attribute information (e.g., model,vendor, etc.), storage device usage statistics (e.g., rated life used,spare sectors consumed, power-on hours), mutable device configurationssettings (e.g., checksum type), administrator assigned attributes (e.g.,assigned disk name), job status of operations (e.g., media scrub, diskzeroing, reconstruct, and copy operations), storage device ownership(e.g., an ownership node having ownership over the storage device),error history of the storage device, and/or a variety of otherinformation. For example, the storage device data structure may compriseone or more tables, which may be populated with such information (e.g.,an attribute info table, an ownership table, a status table, aperformance statistics table, a raid table, one or more connectiontables, and/or other tables). In this way, the storage device reportsmay be aggregated to define storage device data structures for storagedevices (e.g., a single storage device data structure may be defined fora storage device, which may comprise data aggregated from one or morestorage device reports reported from various nodes within the nodecluster connected to the storage device).

It may be appreciated that storage device reports may be aggregatedregardless of whether storage devices are configured with different dataformats and/or whether nodes comprise different operating systems. Inone example, the one or more storage devices within the node cluster maycorrespond to one or more logical unit numbers (LUNs). In anotherexample, a storage device report may comprise storage device informationassociated with a first storage device comprising a first data format(e.g., a LUN) and a second storage device comprising a second dataformat (e.g., a physical storage format) different than the first dataformat. In another example, a first storage device report may bereceived from a first node comprising a first operating system type, anda second storage device report may be received from a second nodecomprising a second operating system type different from the firstoperating system type.

At 316, a cluster view may be generated utilizing one or more storagedevice data structures. It may be appreciated that one or more examplesof cluster views are shown and further described in FIGS. 8-10. In oneexample, a query may be constructed (e.g., the query may be built withone or more query terms based upon one or more query rules), and executeagainst one or more storage device data structures to retrieve storagedevice information to populate a cluster view. In another example,pre-defined queries may be provided for administrative ease (e.g., anadministrator may be provided with pre-defined queries that may beexecuted to generate various cluster views, such as an error clusterview, a storage device summary cluster view, etc.). It may beappreciated that a plethora of queries may be constructed so thatvarious cluster views may be created (e.g., queries may be constructedusing syntax similar to relational database queries).

In one example of a cluster view, a request for the node summary clusterview may be received (e.g., an administrator of the node cluster mayutilize a command prompt and/or a storage administration utilityapplication to request the cluster view). A node summary query may beconstructed, and executed against one or more storage device datastructures to create the node summary cluster view comprising a clusterview of storage devices and storage device connectivity within the nodecluster (e.g., the node summary query may retrieve storage deviceinformation associated with storage devices having an RPM>7200,errors=0, and status=active to create the node summary cluster view). Inanother example of a cluster view, a request for an error cluster viewmay be received. An error query may be constructed, and executed againstone or more storage device data structures to identify one or morestorage devices associated with at least one error to create the errorcluster view. In another example of a cluster view, a request for thestorage device cluster view of a storage device may be received. Astorage device query may be constructed, and executed against one ormore storage device data structures to create a storage device clusterview comprising path connections from the storage device to one or morenodes, storage device configuration and statistical information, errorhistory, and/or other information associated with the storage device. Inanother example, pre-configured commands (e.g., pre-programmed commandline commands) and/or pre-defined orderings of output records (e.g., asorted order in which records within a cluster view may be presented)may be provided for administrative convenience (e.g., a pre-configuredcommand may allow an administrator to quickly retrieve a cluster view ofdefective storage devices that may be ordered/sorted based upon a dateat which such storage devices were designated as defective). At 318, themethod ends.

One embodiment of presenting a cluster view of one or more storagedevices is illustrated by an exemplary method 400 in FIG. 4. At 402, themethod starts. At 404, a request for a cluster view associated with oneor more storage devices within a node cluster may be received. Therequest may correspond to an error cluster view, a storage devicecluster view of a storage device, a node summary cluster view, and/or awide variety of other views associated with storage information from theviewpoint of the node cluster. At 406, a query may be constructed basedupon the request. It may be appreciated that in one example, the querymay be similar to a relational database query that allows a plethora ofdifferent queries to be constructed (e.g., a first query that returnsinformation regarding storage devices with high disk speed, a secondquery that returns information regarding inactive storage devices witherrors, etc.). In one example, an error query may be constructed tosearch storage device data structures for storage devices associatedwith errors. In another example, a storage device cluster view query maybe constructed to extract storage device information from a storagedevice data structure corresponding to the storage device. In anotherexample, a node summary cluster view query may be constructed to extractstorage device information from one or more storage device datastructures based upon various criteria (e.g., a first query that returnsinformation regarding storage devices with a high latency, a secondquery that returns information regarding storage devices that have I/Ooperations above a threshold value).

At 410, the cluster view may be presented. In one example, the clusterview may be presented within a command line interface. In one example,the cluster view may be presented within a user interface, such as astorage administration utility application. Because of the flexibilityprovided by executing custom constructed queries, a user may filter thecluster view. For example, a filter criterion may be received (e.g., auser may desire to filter a node summary cluster view to storage deviceswith a status of inactive). The query may be reconstructed based uponthe filter criterion. The reconstructed query may be executed againstone or more storage device data structures to generate a new clusterview. The new cluster view may be presented (e.g., the new cluster viewmay comprise the original results within the cluster view filtered bystorage devices with a status of inactive). At 412, the method ends.

FIG. 5 illustrates an example of a system 500 configured to generate acluster view 532 of one or more storage devices. System 500 may comprisea node query component 522, a data structure component 526, and/or acluster view component 530. The node query component 522 may beconfigured to query storage application programming interfaces (APIs) onnodes within a node cluster for storage device reports associated withone or more storage devices connected to the respective nodes. In oneexample, the node cluster may comprise node (A), node (B), node (C),node (D), node (Z), and/or other nodes not illustrated. A node withinthe node cluster may be configured to manage data stored on one or morestorage devices connected to the node (e.g., a node may provide a hostcomputing device with read/write access to a storage device). Forexample, node (A) may comprise two path connections 502 to storagedevice (1) and two path connections 504 to storage device (2), and thusmay manage storage operations associated with storage device (1) and(2). Node (B) may comprise two path connections 506 to storage device(3), and thus may manage storage operations associated with storagedevice (3). Node (C) may comprise two path connections 508 to storagedevice (2) and two path connections 510 to storage device (5), wherenode (C) may manage storage operations associated with storage device(2) and (5) and/or may be an ownership node of storage device (5). Node(D) may comprise a single path connection 512 to storage device (4), asingle path connection 514 to storage device (5), and a single pathconnection 516 to storage device (6), and thus may manage storageoperations associated with storage device (4), (5), and (6). Node (Z)may comprise a single path connection 518 to storage device (5) and twopath connections 520 to storage device (N), and thus may manage storageoperations associated with storage device (5) and (N). In this way,storage devices within the node cluster may be connected to one or morenodes that may be configured to manage data stored on such storagedevices. It may be appreciated that in one example, a node may comprisetwo or more path connections to a storage device for redundancyconsiderations in the event a path connection fails.

The node query component 522 may query nodes (A)-(Z), for example inparallel, for storage device reports. It may be appreciated that oneexample of one or more storage device reports is shown and furtherdescribed in FIG. 6. For example, node query component 522 may receive astorage device report (A) from node (A) comprising storage deviceinformation associated with storage device (1) and (2), a storage devicereport (B) from node (B) comprising storage device informationassociated with storage device (3), a storage device report (C) fromnode (C) comprising storage device information associated with storagedevice (2) and (5), a storage device report (D) from node (D) comprisingstorage device information associated with storage device (4)-(6), and astorage device report (Z) from node (Z) comprising storage deviceinformation associated with storage device (5) and (N). In this way, thenode query component 522 may receive storage device reports (A)-(Z) 524.

The data structure component 526 may be configured to aggregate thestorage device reports (A)-(Z) 524 to create storage device datastructures 528 for respective storage devices. It may be appreciatedthat one example of a storage device data structure is shown and furtherdescribed in FIG. 7. In particular, the data structure component 526 mayidentify a storage device within a storage device report (e.g., storagedevice (2) may be identified within storage device report (A) (andwithin storage device report (C) in the illustrated example)). A storagedevice data structure for the storage device may be defined based uponstorage device information within the storage device report (e.g., astorage device data structure (2) for storage device (2) may bepopulated with storage device information corresponding to I/Ooperations between node (A) and storage device (2), latency between node(A) and storage device (2), serial number of storage device (2), etc.).If the storage device data structure is already created, thensupplemental information may be added into the storage device datastructure, non-supplemental redundant information may be discarded,and/or conflicting information may be discarded or used to overwritecurrent information based upon the role or preference of the nodereporting such conflicting information (e.g., storage device informationfor storage device (2) reported by node (C) within storage device report(C) may be aggregated into the storage device data structure (2), whichmay already comprise storage device information populated from storagedevice report (A)). In one example, the data structure component may beconfigured to maintain one or more storage device data structures in anordered sequence, where a storage device data structure represents anaggregate cluster view of a storage device, for example. Maintainingstorage device data structures in an ordered sequence may allow forqueries to be constructed and/or executed against one or more storagedevice data structures to retrieve storage device information that maybe used to generate a cluster view.

The cluster view component 530 may be configured to generate the clusterview 532 utilizing one or more of the storage device data structures528. In one example, the cluster view component 530 may query one ormore storage device data structures to identify one or more storagedevices associated with at least one error to create an error clusterview (e.g., the error cluster view may indicate that storage device (4)has a redundancy error along single path 512, storage device (5) hasredundancy errors along one or more of the two path connections 510 andalong single paths 514 and 518, and storage device (6) has a redundancyerror along single path 516). In another example, the cluster viewcomponent 530 may query one or more storage device data structures tocreate a node summary cluster view comprising a cluster view of storagedevices and storage device connectivity within the node cluster (e.g.,the node summary cluster view may provide storage device information forstorage device (1), (2), and (3) because such storage devices match afilter criterion “status=active and I/O operations>120”). In anotherexample, the cluster view component 530 may query a storage device datastructure associated with a storage device to create a storage devicecluster view comprising path connections of the storage device, storagedevice configuration and statistical information for the storage device,error history for the storage device, and/or other information (e.g., astorage device cluster view for storage device (5) may describe pathconnections 510, 514, and 518, along with configuration and statisticalinformation for storage device (5)). It may be appreciated that avariety of other cluster views may be generated, such as a cluster viewspecifying defective storage devices and/or a cluster view specifyingone or more hot spare storage devices (e.g., storage device(s) ready totake-over in the event of a failure with little to no start up and orlag time).

FIG. 6 illustrates an example 600 of one or more storage device reports.It may be appreciated that storage device report (C) 602 from node (C),storage device report (D) 608 from node (D), and/or storage devicereport (Z) 614 from node (Z) may illustrate examples of storage devicereports that may be reported from node (C), node (D), and node (Z) inthe node cluster illustrated in FIG. 5. In one example, a node querycomponent may have sent a query request to node (C), node (D), node (Z),and/or other nodes within the node cluster for storage device reports. Astorage API on node (C) may have gathered storage device informationassociated with storage device (2) and storage device (5), with whichnode (C) is connected. For example, the storage API may invoke one ormore subsystems to gather a list of path connections 604 (e.g.,information associated with wires (and/or wireless connections)connecting storage device (2) and (5) to one or more nodes, such aslatency along the wire) and/or storage device configuration andstatistical information 606 (e.g., device status, I/O statistics,ownership, errors, etc.). In this way, node (C) may provide the storagedevice report (C) 602 for aggregation by a data structure component.

Similarly, node (D) may generate storage device report (D) 608comprising a list of path connections 610 and/or storage deviceconfiguration and statistical information 612 associated with storagedevice (4), (5), and (6), with which node (D) is connected. Node (Z) maygenerate storage device report (Z) 614 comprising a list of pathconnection 616 and/or storage device configuration and statisticalinformation 618 associated with storage device (5) and (N), with whichnode (Z) is connected. In this way, a data structure component mayaggregate the storage device reports (C), (D), and (Z) to create one ormore data structures (e.g., a data structure for storage device (2), adata structure for storage device (4), a data structure for storagedevice (5), etc.). During aggregation, if storage device informationassociated with storage device (5) conflicts, then it may be appreciatedthat storage device information from node (C) within storage devicereport (C) 602 may be preferred because node (C) is an ownership node ofstorage device (5) (e.g., storage device configuration and statisticalinformation 606 specifies that node (C) is an ownership node of storagedevice (5)). It may be appreciated that one example of a data structure(5) for storage device (5) is shown and further described in FIG. 7.

FIG. 7 illustrates an example 700 of a data structure for a storagedevice. One or more storage device reports (e.g., storage device reports(C), (D), and (Z) of FIG. 6) may be aggregated together to define datastructure (5) 702 for storage device (5). Data structure (5) 702 maycomprise an attribute info table 704, an ownership table 706, aperformance statistics table 710, one or more connection tables (e.g.,connection table (1) 712 associated with a path connection from storagedevice (5) to node (C), connection table (2) 714 associated with a pathconnection from storage device (5) to node (D), and a connection table(3) associated with a path connection from storage device (5) to node(Z)), and/or other tables. During aggregation, if storage deviceinformation associated with storage device (5) conflicts, then it may beappreciated that storage device information from node (C) may bepreferred because node (C) is an ownership node of storage device (5).For example, node (C) may be an ownership node that may perform asubstantial percentage of I/O operations with regard to storage device(5), whereas node (D) may be a backup node that does not perform I/Ooperations with regard to storage device (5) until a failure of node (C)occurs. Thus, I/O operation data from node (C) may be preferred over I/Ooperation data from node (D). In this way, various storage devicereports may be aggregated to populate data structure (5), where somedata may be added, some data may be discarded, and/or some data may beused to overwrite other data.

FIG. 8 illustrates an example 800 of a node summary cluster view 802.The node summary cluster view 802 may provide a variety of storagedevice information based upon various filter criteria that may be usedto construct different queries (e.g., a plethora of node summary clusterviews with different storage device information may be generated fromdifferent queries). The node summary cluster view 802 may be generatedbased upon querying one or more storage device data structures using aquery string constructed from one or more filter criteria (e.g., “findstorage devices where within performance statistics table I/Ooperations>100 and error count>2”; “find storage devices where withinattribute info table RPM>7200 and within raid table RAID group=0”; “findstorage devices assigned for node B”; “find storage devices with status=hot spare”; and/or a plethora of other queries may be used to generatethe node summary cluster view 802). In one example, the node summarycluster view 802 may provide path connection data for storage devices(e.g., information regarding wires (and/or wireless connections)connecting a storage device to a node, such as latency, wire type,etc.). In this way, configuration errors may be identified. For example,if a redundancy policy is in place where a storage device is to beconnected to a node with at least two path connections, then single pathconnections may be flagged as potential configuration errors (e.g.,single path connections 804, 806, 808, and 810).

In another example, the node summary cluster view 802 may providestorage device information for storage devices associated with I/Ooperations above a predetermined threshold that have an error countabove 2 (e.g., “find storage devices where within performance statisticstable I/O operations>100 and error count>2”). In this way, the nodesummary cluster view 802 may provide storage device informationassociated with frequently access storage devices that have errors. Itmay be appreciated that the node summary cluster view 802 may befiltered to provide more granular results. For example, the node summarycluster view 802 of frequently accessed storage devices that have errorsmay additionally be filtered based upon storage devices connected to atleast 4 nodes (e.g., “find storage devices where within performancestatistics table I/O operations>100 and error count>2 and connectiontable count>4”). Thus, the original query may be restructured, andexecuted against one or more storage device data structures to determinea new node summary cluster view.

FIG. 9 illustrates an example 900 of an error cluster view 902. Theerror cluster view 902 may provide various error information, such asdisk error information, I/O operation failures, connection failures,failure to meet a redundancy policy, etc. For example, error clusterview 902 may indicate that a redundancy policy (e.g., a redundancypolicy that is not met unless at least two path connections connect astorage device and a node) is violated by one or more storage devicesbecause 904 storage device (4) is connected to node (D) through a singlepath connection, 906 storage device (5) is connected to node (D) througha single path connection, 908 storage device (5) is connected to node(Z) through a single path connection, and 910 storage device (6) isconnected to node (D) through a single path connection (e.g., pathconnections 512, 514, 516, and 518 of FIG. 5). The error cluster view902 may have been generated utilizing one or more storage device datastructures. For example, storage device data structures may have beenqueried to identify storage devices associated with errors (e.g., “findstorage devices where within connection table path errors>0”).

FIG. 10 illustrates an example 1000 of a storage device cluster view1002. The storage device cluster view 1002 may provide storage deviceinformation for storage device (5). For example, a storage device datastructure for storage device (5) may be queried (e.g., one or moretables within data structure (5) 702 of FIG. 7 may be queried) forstorage device information. In this way, storage device cluster view1002 may be populated with storage device information, such as serialnumber, capacity, I/O performance statistics, path connection, errors,and a variety of other information).

It will be appreciated that processes, architectures and/or proceduresdescribed herein can be implemented in hardware, firmware and/orsoftware. It will also be appreciated that the provisions set forthherein may apply to any type of special-purpose computer (e.g., filehost, storage server and/or storage serving appliance) and/orgeneral-purpose computer, including a standalone computer or portionthereof, embodied as or including a storage system. Moreover, theteachings herein can be configured to a variety of storage systemarchitectures including, but not limited to, a network-attached storageenvironment and/or a storage area network and disk assembly directlyattached to a client or host computer. Storage system should thereforebe taken broadly to include such arrangements in addition to anysubsystems configured to perform a storage function and associated withother equipment or systems.

In some embodiments, methods described and/or illustrated in thisdisclosure may be realized in whole or in part on computer-readablemedia. Computer readable media can include processor-executableinstructions configured to implement one or more of the methodspresented herein, and may include any mechanism for storing this datathat can be thereafter read by a computer system. Examples of computerreadable media include (hard) drives (e.g., accessible via networkattached storage (NAS)), Storage Area Networks (SAN), volatile andnon-volatile memory, such as read-only memory (ROM), random-accessmemory (RAM), EEPROM and/or flash memory, CD-ROMs, CD-Rs, CD-RWs, DVDs,cassettes, magnetic tape, magnetic disk storage, optical or non-opticaldata storage devices and/or any other medium which can be used to storedata.

Another embodiment (which may include one or more of the variationsdescribed above) involves a computer-readable medium comprisingprocessor-executable instructions configured to apply one or more of thetechniques presented herein. An exemplary computer-readable medium thatmay be devised in these ways is illustrated in FIG. 11, where theimplementation 1100 comprises a computer-readable medium 1108 (e.g., aCD-R, DVD-R, platter of a hard disk drive, flash drive, etc.), on whichis encoded computer-readable data 1106. This computer-readable data 1106in turn comprises a set of computer instructions 1104 configured tooperate according to the principles set forth herein. In one suchembodiment, the processor-executable instructions 1104 may be configuredto perform a method 1102, such as at least some of the method 300 ofFIG. 3 and/or method 400 of FIG. 4, for example, and/or at least some ofa system, such as at least some of the system 500 of FIG. 5, forexample. Many such computer-readable media may be devised by those ofordinary skill in the art that are configured to operate in accordancewith the techniques presented herein.

Although the disclosure has been shown and described with respect to oneor more implementations, equivalent alterations and modifications willoccur to others skilled in the art based upon a reading andunderstanding of this specification and the annexed drawings. Thedisclosure is intended to include such modifications and alterations. Inparticular regard to the various functions performed by the abovedescribed components (e.g., elements, resources, etc.), the terms usedto describe such components are intended to correspond, unless otherwiseindicated, to any component which performs the specified function of thedescribed component (e.g., that is functionally equivalent), even thoughnot structurally equivalent to the disclosed structure which performsthe function in the herein illustrated exemplary implementations of thedisclosure. Furthermore, to the extent that the terms “includes”,“having”, “has”, “with”, or variants thereof are used in either thedetailed description or the claims, such terms are intended to beinclusive in a manner similar to the term “comprising.” Also,“exemplary” means an example, not the best; “or” is intended to beinclusive not exclusive; “a” and/or “an” mean “one or more” unlessspecified otherwise and/or clear from context to be directed to asingular form; and at least one of A and B and/or the like generallymeans A or B or both A and B.

What is claimed is:
 1. A method for providing a cluster view for one ormore storage devices, comprising: receiving a request for a cluster viewof a node cluster, the node cluster comprising a set of nodes configuredto manage storage devices; constructing a query based upon the request;executing the query against a set of storage device data structures toobtain a storage device information result, the set of storage devicedata structures comprising storage device information derived fromstorage reports queried from the set of nodes; constructing a clusterview based upon the storage device information result; and presentingthe cluster view.
 2. The method of claim 1, the constructing a clusterview comprising: constructing a summary cluster view as the clusterview, the summary cluster view comprising a first device to nodeconnection summary and a second device to node connection summary. 3.The method of claim 2, the first device to node connection summarycorresponding to a first storage device and a first node, the seconddevice to node connection summary corresponding to a second storagedevice and the first node.
 4. The method of claim 2, the first device tonode connection summary corresponding to a first storage device and afirst node, the second device to node connection summary correspondingto a second storage device and a second node.
 5. The method of claim 2,the first device to node connection summary corresponding to a firststorage device and a first node, the second device to node connectionsummary corresponding to the first storage device and a second node. 6.The method of claim 1, the constructing a cluster view comprising:constructing an error cluster view as the cluster view, the errorcluster view comprising an error associated with a first storage device.7. The method of claim 6, the error comprising a redundancy errorspecifying that the first storage device is connected to a first nodeaccording to a single path configuration and not a redundant pathconfiguration.
 8. The method of claim 1, the constructing a cluster viewcomprising: constructing a storage device cluster view as the clusterview, the storage device cluster view comprising at least one of a pathconnection from a first storage device to one or more nodes, storagedevice configuration information for the first storage device, storagedevice statistical information for the first storage device, or an errorhistory for the first storage device.
 9. The method of claim 1, theconstructing a cluster view comprising: constructing a storage devicesummary cluster view as the cluster view, the storage device summarycluster view comprising a cluster view of storage devices and storagedevice connectivity within the node cluster.
 10. The method of claim 9,the constructing a storage device summary cluster view comprising:obtaining a first storage device information result from a first storagedata structure for a first storage device; obtaining a second storagedevice information result from a second storage data structure for asecond storage device; and constructing the storage device summarycluster view based upon the first storage device information result andthe second storage device information result.
 11. The method of claim 1,the cluster view comprising first storage device attribute informationfor a first storage device managed by a first node and second attributeinformation for a second storage device managed by a second node. 12.The method of claim 1, the cluster view comprising first storage deviceperformance statistics information for a first storage device managed bya first node and second storage device performance statisticsinformation for a second storage device managed by a second node. 13.The method of claim 1, the cluster view comprising first storage deviceconnection information for a first storage device managed by a firstnode and second storage device connection information for a secondstorage device managed by a second node.
 14. The method of claim 1, thecluster view comprising first storage device ownership information for afirst storage device managed by a first node and second storage deviceownership information for a second storage device managed by a secondnode.
 15. A system for providing a cluster view for one or more storagedevices, comprising: a cluster view component configured to: receive arequest for a cluster view of a node cluster, the node clustercomprising a set of nodes configured to manage storage devices;construct a query based upon the request; execute the query against aset of storage device data structures to obtain a storage deviceinformation result, the set of storage device data structures comprisingstorage device information derived from storage reports queried from theset of nodes; construct a cluster view based upon the storage deviceinformation result; and present the cluster view.
 16. The system ofclaim 15, the cluster view comprising a summary cluster view, thesummary cluster view comprising a first device to node connectionsummary and a second device to node connection summary.
 17. The systemof claim 15, the cluster view comprising an error cluster view, theerror cluster view comprising an error associated with a first storagedevice.
 18. The system of claim 15, the cluster view comprising astorage device cluster view, the storage device cluster view comprisingat least one of a path connection from a first storage device to one ormore nodes, storage device configuration information for the firststorage device, storage device statistical information for the firststorage device, or an error history for the first storage device. 19.The system of claim 15, the cluster view comprising a storage devicesummary cluster view, the storage device summary cluster view comprisinga cluster view of storage devices and storage device connectivity withinthe node cluster.
 20. A computer readable medium comprising instructionswhich when executed perform a method for providing a cluster view forone or more storage devices, comprising: receiving a request for acluster view of a node cluster, the node cluster comprising a set ofnodes configured to manage storage devices; constructing a query basedupon the request; executing the query against a set of storage devicedata structures to obtain a storage device information result, the setof storage device data structures comprising storage device informationderived from storage reports queried from the set of nodes; constructinga cluster view based upon the storage device information result; andpresenting the cluster view.